Method of making corrugated metal culverts



July 26, 1938. E. F. LUNDEEN 2,124,382

METHOD OF MAKING CORRUGATED METAL CULVERTS Original Filed Oct. 17, 1935 INVENTOR. Erzwssr 15" Luumsnv.

al. M

ATTORNEYS.

Patented July 26, 1938 I UNITED]. STATES 2,124,882 METHOD or MAKING CORRUGATEDMETAL CULVE RTS Ernest F. Lundeen, Middletown, Ohio, assignor to The American Rolling Mill Company, Middletown, Ohio, a corporation of Ohio Original application October 17, 1935. Serial No.

45,461. Patent No. 1937. 1936, Serial No. 89,796

Divided and this 2,094,898, dated October 5,

application July 9,

3 Claims. (01. 29-1482) This application is a division of Serial No. 45,461 filed Oct. 17, 1935, issued October 5, 1937, as Patent No. 2,094,898.

My invention relates to corrugated culverts in which a paving or lining is formed which resists abrasive and corrosive action in the same.

There are two general types of so called paved corrugated metal culverts, which have gone largely into general commercial use. One of these is built according to the Cushman Patent No. 1,652,703, dated Dec. 13, 1927, and Patent No. 1,735,732, dated November 12, 1929; the other is built in accordance with the Freeze Patent No. 1,984,125, dated Dec. 11, 1934, and No. 2,006,888, dated July 2, 1935.

A'difliculty attendant upon either the Cushman practice or the Freeze practice, is the use of an asphalt which will bond with the metal pipe, will resist abrasion, and at all temperatures normally encountered will remain in close adherent contact with the metal of the pipe.

It has been proposed by Coifman in Patent No. 1,862,332, to secure an asbestoslayer to a metal sheet by coating the sheet with hot metal such as tin or zinc, and using this hot metal to bond the asbestos layer or felted body to the sheet.

I have found that if a sheet is so coated with an asbestos felt pad, and this pad is saturated with asphalt, that a body is formed upon which the regular paving of either the Cushman type or the Freeze type may be applied with greater permanence. I have found that the asbestos felt covered sheet, saturated with suitable asphalt, can be corrugated in the usual manner, and formed into culvert pipe in the usual manner, after which the paving either of the Cushman type or Freeze type is applied.

An asbestos felt which is provided with some organic fibrous material to make it stronger, and has binders of organic origin such as starch or the like, operates with particular success, in my practice, because the organic fiber and binder will be driven ofiduring the bonding operation by the temperature of the hot coating metal, thus making a porous sheet which will readily take up the saturating asphalt.

I accomplish my objects by that certain structure and practice of which examples will be given in the following specification, the invention inherent therein being set forth in the appended claims to which reference is made.

In the drawing:-

Figure 1 shows a sheet which has been coated with asbestos felt by bonding with hot metal coating applied to the sheet.

Fig. 2 is a. view of the said sheet in section showing the bonded, asphalt saturated pad in place.

Fig. 3 is a like view showing the same sheet corrugated.

Fig. 4 is a finished culvert showing one type of paving.

Fig. 5 is another culvert showing a different type of paving.

I am aware that it has been proposed to apply a felt sheet which has been saturated with asphalt to a sheet of metal to which the sheet is bonded with asphalt. I am also aware that the Cofiman method of bonding an asbestos pad to a metal sheet contemplates also the possibility of an additional coating or saturation of the asbestos covering after it has been applied.

My invention is related to applying these fundamental ideas to the structure of culverts of corrugated metal, together with the necessary additions and modifications required to do so. The finalstructure which I provide possesses valuable qualities not apparent from the knowledge which I have above imputed to the prior art, and will be developed as this description proceeds.

Referring to the drawing, the flat sheet of metal I, is passed through a galvanizing bath of usual zinc or spelter. The temperature of the spelter will be at 750 to 850 degrees Fahr. The coated sheet is fed from the galvanizing pot while the zinc is still highly molten through a set of rolls. Dependent upon whether one or both sides of the sheet are to be treated, webs of asbestos paper (preferably weighing five or six pounds to the square foot) are run under and over the sheet of coated metal. It is particularly important to have the asbestos paper dry when this operation takes place. The action of the rolls is to squeeze the paper against the sheet and bring about the condition that the spelter as it hardens bonds in with the fibres of the asbestos paper, which are imbedded in the spelter.

Due to the heat of the spelter, the asbestos paper as it emerges from the rolls is altered by the heat, with the goat hair or other organic fibre, and the binder of starch or the like, burned away, leaving the sheet more porous than it would be otherwise.

A cooling wheel is employed, into which the sheets are fed from the bonding rolls, and after passing over the cooling wheel the sheets are roller levelled, and the edges trimmed so as to be free of overhanging fibrous material.

The sheet is now in the form illustrated in Fig. l, with the metal body I, the spelter coating 2, and the fibrous pad 3 all three bonded together by the hardened spelter.

The next stage is to saturate the asbestos pad. To do this the covered sheet is heated up to preferably around 350 degrees Fahr. and passed between rolls supplied with saturating asphalt, which is kept at around 450 degrees Fahr. The sheet is thenpassed between squeeze rolls, which squeezes out any excess saturant, whereupon the sheets pass to a second cooling wheel. This results in the sheet shown in Fig. 2, wherein the saturated pad is indicated at I.

Should the covering be located on both sides of the sheet, it will be passed through a saturating bath of the asphalt rather than the roll type of applicator, whereupon the squeeze roll operation will follow as in the first case. It is also feasible to spray the saturating asphalt on the sheets.

When the sheets have cooled down, say so that the hand can be placed upon them, which may be around 130 degrees Fahr. they pass through corrugating rolls in the usual manner for zinc coated sheets, and are ready for shipment to the plant where the culvert is made, or for making into culverts immediately, as the case may be.

Although nested in shipment, as will be necessary for economy, the corrugated sheets will not adhere to each other because there is a minimum of coating on the surface of the saturated asbestos paper. I show in Fig. 3 the corrugated sheet, the corrugations being indicated at 5.

The saturating asphalt is best one which has a ball and ring melt point of between 125 and 145 degrees Fahr. and a peneration at 25 degrees centigrade, 100 grams, five seconds, of 30 to 50.

The culvert sections 6 are formed in the usual manner from the corrugated sheets after which they are dipped in coating asphalt. This asphalt preferably is one having a ball and ring melt point of 200 degrees to 210 degrees Fahr., and penetration at 32 degrees Fahr. 100 grams,

five seconds of around 35, and at 115 degrees- Fahr. of around 75. It will be noted that this coating asphalt is much higher melt point than the saturating asphalt, but it will bond with the saturating asphalt. I apply the coating at around 3'75 degrees Fahr.

After coating and while the coating is hotand plastic, I insert the premolded asphaltic paving pads I, which as noted in the Freeze patent heretofore identified, will have their faces as applied to the corrugated culvert section, similarly corrugated which facilitates bonding of the pads in place. As is usually practiced, the pads are forced home into the culvert sections by rolling them down firmly. The coating asphalt adhesively secures them in place.

The culvert section or corrugated pipe is then given another dip in the coating asphalt and permitted to drain as in the first instance.

It can be seen that the asphalt in the pad and as a coating on the asbestos paper, and as permeating the paper, forms a continuous bonding medium for holding the several layers bonded together, and that the metal which bonds the asbestos paper to the corrugated sheet completes a strong and eflective bonding of all of the superimposed layers to the metal.

Instead of using pads, a series or dips and drains of the corrugated pipe, permitting the coating to harden somewhat in between dips, will give a paving in the culvert which will still neces- 'pipe and flowing in a fresh body of the coating asphalt. Or the pipe section or joined sections can be dipped into coating asphalt and not drained but laid on their sides so that a pool or pools are formed.

The culvert having a paving formed by dipping is illustrated in Fig. 4, in which there is shown a level floor formed in the last noted manner, this being the practice in the Cushman t p of pavin By explaining several modes or variants in procedure, I do not wish to be understood as representing that these are the only practical ones, as several other practices may be employed to produce my final product in its several forms.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. That method of forming a paved culvert which consists in applying hot spelter to a sheet of metal while the same is flat, and while the spelter is molten applying thereto a web of asbestos material, roller levelling said product, heating said product and applying an asphaltic saturant thereto, then corrugating the sheet, forming a culvert section of said sheet, and then applying a coating of asphaltic material to the interior at least of the culvert section, so as to form a paving therein.

2. That method of forming a paved culvert which consist in applying hot spelter to a sheet of metal while the same is flat, and while the spelter is molten applying thereto a web of asbestos material, roller levelling said product, heating said product and applying an asphaltic saturant thereto, then corrugating the sheet, forming a'culvert section of said sheet, and then applying a coating of asphaltic material to the interior at least of the culvert section, and while the coating is hot, applying thereover a pad of asphaltic material, and causing a surface of said pad to conform to the corrugations of the culvert section area to which said pad is applied.

3. That method of forming a paved culvert which consists in applying hot spelterto a sheet of metal while the same is flat, and while the spelter is molten applying thereto a web of asbestos material, roller levelling said product, heating said product and applying an asphaltic saturant thereto, then corrugating the sheet, forming a culvert section of said sheet, and then applying a coating of asphaltic material to the interior at least of the culvert section, said coating being permitted to form in a pool or pools to form a corrugation levelling area or areas in the culvert section.

ERNEST F. LUNDEEN. 

